36 INFECTIOUS AND PARASITIC DISEASES. 



him at the time of his fever did remark that there was 

 some shght evidence of cardiac injury. But even this 

 evidence of the connection between his present trouble 

 and the earlier typhoid fever is now no longer necessary ; 

 we have learned through experience the connection. 

 Are typhoid bacilli causing the present trouble ? Assur- 

 edly not ! The original cause was an inflammation of the 

 heart valves from the typhoid bacilli, most likely, or 

 some other microbe that gained an entrance into the 

 blood during his attack of typhoid. The lesion of 

 the heart, to all appearances, healed. But a cicatrix 

 remained, that, according to the manner of all cica- 

 trices, continued to contract, until through the disability 

 it produced in the functioning of the heart, gave rise to 

 symptoms. Substantially the same history is obtained 

 in many cases of Bright's disease (chronic nephritis), 

 the antecedent disease being either scarlet fever, 

 measles, diphtheria, or typhoid fever. 



We have used the word infectious a number of times, 

 but purposely have avoided using another word, 

 namely, contagious^ on account of the many loose inter- 

 pretations that are given it. To us it seems best to 

 speak of a contagion, or a contagious disease, only 

 when the microbe is readily communicable from person 

 to person by mediate or immediate contact. The 

 term should be used as descriptive of a quality of the 

 germ or of a microbic disease. It should not be used 

 synonymously with infectious or infection; in fact, if 



